1. Field of the Invention
The present invention relates to a flexible printed circuit board and a liquid crystal display having the flexible printed circuit board. More particularly, the present invention relates to a flexible printed circuit board capable of preventing disconnection due to thermal expansion thereof and improving assembly efficiency thereof, and a liquid crystal display having the flexible printed circuit board.
2. Description of the Related Art
Recently, information-processing devices have been rapidly developed in a trend with various architectures, functions and faster information processing speed. Information processed in these information-processing devices has an electrical signal format. In order to visually confirm information processed in the information-processing device, a display device for acting as an interface is required.
A liquid crystal display is one of the information-processing devices, and uses liquid crystal so as to display an image. The liquid crystal display has thin thickness, lightweight, low power consumption, low driving voltage, etc. Therefore, the liquid crystal display is widely used in various fields.
The liquid crystal display includes a display unit for displaying an image and a backlight assembly for providing light to the liquid crystal display panel.
In order to display the image using a liquid crystal display panel, the display unit converts image data provided from a driving circuit into a driving signal suitable for driving the liquid crystal display panel, and timely applies the driving signal to the liquid crystal display panel.
For this purpose, the display unit demands a process that processes the image data in a driving chip before the image data is applied to the liquid crystal display panel. That is, the driving chip is connected to the driving circuit so as to receive the image data and timely apply the received image data to data and gate lines of the liquid crystal display panel.
The display unit includes a data side tape carrier package (TCP) on which a data driving chip is mounted by a chip-on-film (COF) method and a gate side TCP on which a gate driving chip is mounted by the COF method.
In recent, in order to reduce a cost, a chip-on-glass (COG) method that directly mounts the data and gate driving chips onto the liquid crystal display is widely applied. The data driving chip is mounted onto a data side of the liquid crystal display panel and connected to data lines, and the gate driving chip is mounted onto a gate side of the liquid crystal display panel and connected to gate lines.
The liquid crystal display panel on which the data and gate driving chips are mounted is electrically connected to the driving circuit via the flexible printed circuit board. Particularly, conductive lines of the flexible printed circuit board and input terminals of the liquid crystal display panel are compressed to each other, so that the conductive lines are electrically connected to the input terminals through an anisotropic conductive film (ACF) disposed between the conductive lines and the input terminals.
However, since a process that compresses the conductive lines of the flexible printed circuit board and the input lines of the liquid crystal display panel is performed under high temperature, the flexible printed circuit board may be expanded due to the heat. As a result, an electrical connection between the conductive lines of the flexible printed circuit board and the input lines of the liquid crystal display panel may be shorted or opened.
Moreover, the flexible printed circuit board coupled to the liquid crystal display panel is outwardly bent to the rear surface of the backlight assembly, and electrically connected to the driving circuit. Thus, a size of the liquid crystal display may increase and assembly efficiency thereof may be deteriorated because the flexible printed circuit board is bent in a predetermined curvature.